- TWO CONVENIENT METHODS FOR THE GENERATION OF "METHYLENE MELDRUM'S ACID" FOR DIELS- ALDER REACTIONS.
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The transient isopropylidene methylenemalonate can be easily generated by treating either Meldrum's acid or diisopropylidene methylenedimalonate with formaldehyde, and trapped by reactive dienes.
- Buzinkai, John F.,Hrubowchak, David M.,Smith, Francis X.
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Read Online
- CANNABINOID DERIVATIVES, PRECURSORS AND USES
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The present disclosure relates to new cannabinoid derivatives and precursors and processes for their preparation. The disclosure also relates to pharmaceutical and analytical uses of the new cannabinoid derivatives.
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Page/Page column 21; 26
(2021/03/19)
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- METHODS OF SYNTHESIS OF (1R,2R,5R)-5-AMINO-2-METHYLCYCLOHEXANOL HYDROCHLORIDE AND INTERMEDIATES USEFUL THEREIN
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Provided herein are methods and intermediates for making (lR,2R,5R)-5-amino-2- methylcyclohexanol hydrochloride, which are useful for the preparation of compounds useful for the treatment of a disease, disorder, or condition associated with the JNK pathwa
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Paragraph 0047
(2017/02/24)
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- BORON-BASED CYCLOADDITION CATALYSTS AND METHODS FOR THE PRODUCTION OF BIO-BASED TEREPHTHALIC ACID, ISOPHTHALIC ACID AND POLY (ETHYLENE TEREPHTHALATE)
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Methods for producing cycloaddition products comprising: reacting a diene with a dienophile in the presence of one or more boron-based catalysts of Formula I or Formula II are provided. In particular, the methods can be used to prepare 4-methyl-3-cyclohexene- 1-carboxylic acid and 3-methyl-3-cyclohexene-l-carboxylic acid, including bio-based versions thereof. The cycloaddition products can be advantageously used in the production of terephthalic acid and isophthalic acid, and ultimately, poly(ethylene terephthalate), and bio-based versions thereof. Formula I Formula II
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Paragraph 00172; 00173
(2017/04/11)
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- Synthesis of 1,3-Cycloalkadienes from Cycloalkenes: Unprecedented Reactivity of Oxoammonium Salts
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Few methods allow for the direct conversion of cycloalkenes into cycloalkadienes with high chemo- and regioselectivity. Herein, we report a convenient one-pot process for this transformation that involves the unprecedented N-preferential group transfer of N-oxoammonium salts to cycloalkenes, followed by Cope elimination, to afford cycloalkadienes at room temperature and pressure.
- Nagasawa, Shota,Sasano, Yusuke,Iwabuchi, Yoshiharu
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supporting information
p. 13189 - 13194
(2016/10/30)
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- Method for preparation of 4-methylcyclohex-3-ene-1-carboxylic acid from 4-methyl-3-cyclohexene-1-carbaldehyde
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The invention relates to a method for preparation of 4-methylcyclohex-3-ene-1-carboxylic acid by selective oxidation of 4-methyl-3-cyclohexene-1-carbaldehyde. Specifically, the method includes: under an alkaline condition, under the action of a supported
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Paragraph 0022
(2017/04/25)
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- Polyelectrolyte-catalyzed Diels–Alder reactions
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Imidazolium-based poly(ionic liquids) bearing bromide and bis(trifluoromethane)sulfonimide as counteranions [poly(ViEIm)Br and poly(ViEIm)NTf2] derived from reversible addition fragmentation chain transfer (RAFT) polymerization techniques are u
- Pothanagandhi, Nellepalli,Sivaramakrishna, Akella,Vijayakrishna, Kari
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p. 132 - 136
(2016/08/05)
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- SOLID FORMS OF 2-(TERT-BUTYLAMINO)-4-((1R,3R,4R)-3-HYDROXY-4-METHYLCYCLOHEXYLAMINO)-PYRIMIDINE-5-CARBOXAMIDE, COMPOSITIONS THEREOF AND METHODS OF THEIR USE
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Provided herein are formulations, processes, solid forms and methods of use relating to 2- (tert-butylamino)-4-((lR,3R,4R)-3-hydroxy-4-methylcyclohexylamino)-pyrimidine-5- carboxamide.
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Paragraph 00458
(2015/11/02)
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- NOVEL COMPOUNDS
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Novel rapamycin analogues and methods for their production with FKBP and/or MIP inhibitory activity with reduced mTOR inhibitory activity with therapeutic potential e.g. as bacterial virulence inhibitors.
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Page/Page column 28
(2015/02/02)
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- Dehydro-aromatization of cyclohexene-carboxylic acids by sulfuric acid: Critical route for bio-based terephthalic acid synthesis
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A novel dehydro-aromatization reaction under mild reaction conditions was successfully developed using sulfuric acid as a cost-effective and efficient oxidant. This reaction simplified the synthesis of terephthalic acid (TA, an important aromatic monomer precursor) from biomass-derived isoprene and acrylic acid.
- Wang, Fei,Tong, Zhaohui
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p. 6314 - 6317
(2014/01/23)
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- SuperQuat 5,5-dimethyl-4-iso-propyloxazolidin-2-one as a mimic of Evans 4-tert-butyloxazolidin-2-one
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The incorporation of a gem-dimethyl group at the 5-position of a chiral oxazolidinone biases the conformation of the adjacent C(4)-stereodirecting group such that the gem-dimethyl-4-iso-propyl combination mimics a C(4)-tert-butyl group, providing higher levels of stereocontrol than a simple 4-iso-propyloxazolidinone. The generality of this principle is demonstrated with applications in stereoselective enolate alkylations, kinetic resolutions, Diels-Alder cycloadditions and Pd-catalysed asymmetric acetalisation reactions. The Royal Society of Chemistry 2006.
- Bull, Steven D.,Davies, Stephen G.,Garner, A. Christopher,Kruchinin, Dennis,Key, Min-Suk,Roberts, Paul M.,Savory, Edward D.,Smith, Andrew D.,Thomson, James E.
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p. 2945 - 2964
(2008/02/09)
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- Toward Diels-Alder reactions on a solid support using polymer bound N-substituted 3-hydroxy-4,4-dimethyl-2-pyrrolidinone acrylate derivatives
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Several N-substituted 3-hydroxy-4,4-dimethyl-2-pyrrolidinone acrylate derivatives, selected to allow their attachment to a polymer, have been prepared and tested as dienophiles in the Diels-Alder reaction. The experiments, performed under TiCl4 catalysis in solution or the solid phase with isoprene and cyclopentadiene as dienes, pointed out the difficulties associated with some of these compounds that failed to give the corresponding cycloadduct. 13C NMR studies provided some evidence regarding the nature of the interactions between the acrylate compounds and TiCl4. It appears that the outcome of the reaction is dependent on the acrylate structure and that the 4-(3-hydroxy-4,4-dimethyl-2-oxopyrrolidin-1-yl)benzoic acid acrylate derivatives are highly efficient to give the cycloadduct in good yield and with high regio- or endoselectivity in both solution and solid-phase reaction conditions. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
- Akkari, Rhalid,Calmes, Monique,Martinez, Jean
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p. 2441 - 2450
(2007/10/03)
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- (R)- or (S)-4-(3-hydroxy-4,4-dimethyl-2-oxopyrrolidin-1-yl)benzoic acid as a new chiral auxiliary for solid phase asymmetric Diels-Alder reactions
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The synthesis of enantiopure (R)- and (S)-4-(3-hydroxy-4,4-dimethyl-2- oxopyrrolidin-1-yl)benzoic acid is described and the corresponding supported chiral acrylate derivative has been used as a dienophile in solid phase asymmetric Diels-Alder reactions wi
- Akkari, Rhalid,Calmes, Monique,Escale, Francoise,Iapichella, Julien,Rolland, Marc,Martinez, Jean
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p. 2515 - 2525
(2007/10/03)
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- Diels-Alder reactions in pyridinium based ionic liquids
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Diels-Alder reactions have been investigated in pyridinium based ionic liquids. These solvents are found to be more effective compared to the organic solvent studied, in enhancing the reaction rate and product yields. Recycled ionic liquids also gave exce
- Xiao, Ying,Malhotra, Sanjay V.
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p. 8339 - 8342
(2007/10/03)
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- Chemical transformation of substrates using nonmetallic, organic catalyst compositions
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A method is provided for catalytically transforming a functional group within a first reactant by reaction with a second reactant in the presence of a nonmetallic, organic catalyst composition composed of a heteroatom-containing activator and an acid, or a salt of a heteroatom-containing activator and an acid. Exemplary first reactants are α,β-unsaturated carbonyl compounds such as α,β-unsaturated ketones and α,β-unsaturated aldehydes. The heteroatom of the activator is a Group 15 or Group 16 element such as nitrogen, oxygen, sulfur or phosphorus, and exemplary heteroatom-containing activators are amines. Chiral heteroatom-containing activators can be used to catalyze enantioselective reactions, such that a chiral product is obtained from a chiral or achiral starting material in enantiomerically pure form.
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- Zirconocene-catalyzed cationic Diels-Alder reactions
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In situ prepared Cp2ZrCl+ catalyzes the formation of dioxolenium ions from α,β-unsaturated epoxy esters. As a consequence of this activation process, acrylate, methacrylate and crotonate derivatives undergo a rapid and stereoselective cationic [4+2] cycloaddition with a wide range of dienes. Ring-extended carboxylic acid derivatives are formed in 1-7 h at 0-21°C and in 50-90% yield after saponification of the intermediate diol esters. Simple Lewis acid catalysis by Cp2ZrCl+ can be excluded on the basis of the experimental results.
- Wipf, Peter,Xu, Wenjing
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p. 4551 - 4562
(2007/10/02)
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- ORGANOMANGANESE (II) REAGENTS XIV: A SHORT AND EFFICIENT SYNTHESIS OF DIASTEREOISOMERIC (+/-)-α-BISABOLOLS AND (+/-)-CHLORPHENOXAMINE
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Diastereomeric (+/-)-α-bisabolols (7), a sesquiterpenoid alcohol, and (+/-)-chlorphenoxamine (12), an antihistamine, have been prepared in excellent yields.Both these short and convenient syntheses involve as a key step the one-pot elaboration of a dissymetrical tertiary alcohol via an organomanganese reagent (5 to 7 and 9 to 10 respectively).
- Cahiez, Gerard,Rivas-Enterrios, Jose,Clery, Patrick
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p. 3659 - 3662
(2007/10/02)
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- STEREOCHEMICAL CONTROL BY CARBOXYLATE GROUPS IN HOMOGENEOUS HYDROGENATION
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The stereochemistry of hydrogenation of a range of unsaturated cyclohexane-carboxylic acids and their esters has been investigated, employing either bis(1,4-diphenylphosphino)butanerhodium or pyridine(tricyclohexylphosphine)iridium based cationic catalysts in CH2Cl2.For methyl 3-methylcyclohex-2-enecarboxylate, highly selective reduction to the trans-product was achieved in both cases, whereas the isomeric methyl 3-methylenecyclohexanecarboxylate gave appreciable amounts of the cis-isomer.A predominance of trans-isomer was also achieved in the reduction of methyl 4-methylcyclohex-3-ene carboxylate, in a rather slower reaction.Reductions with D2 revealed that considerable isomerisation of the olefinic double bond occurred during hydrogenation.The corresponding unsaturated acids were reduced with moderate to high selectivity but reaction was either very slow, or ceased after a few turnovers.Related cyclohexadienecarboxylates were unreactive to homogeneous hydrogenation with cationic catalysts.
- Brown, John M.,Hall, Stephen A.
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p. 333 - 342
(2007/10/02)
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- SYNTHESIS OF CYCLOHEXENYL-SUBSTITUTED ACRYLIC AND 3-HYDROXYPROPIONIC ACIDS AND THEIR HOMOLOGS
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The corresponding 3-cyclohexenyl-substituted Z- and E-acrylic and 3-hydroxypropionic acids were synthesized from 3-cyclohexene-1-carbaldehyde and its methyl derivatives.Dehydration of the products under various conditions leads to the formation of the E isomers of the substituted acrylic acid and also isomerization, aromatization, and cyclization products.
- Gramenitskaya, V. N.,Inozemtseva, L. V.,Koz'mina, E. A.,Vul'fson, N. S.
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p. 2260 - 2267
(2007/10/02)
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